Question to Sigma 18-50 f2.8 owners

[Coco-Puffs]

I'm torn between the 17-70 and 18-50 f2.8. I keep on hearing awesome reviews about the 17-70. Then here's this constant f2.8 lens thats in the range I want. BUT, I keep on seeing focus issues ALL OVER the internet.

Now, my question to my fellow POTN member is the 18-50 f2.8 (or wasnt-happy-with-it-and-returned-owners), are you, or are you not,happy with this lens?
If you aren't happy with it, can you tell me why please??

I just wish Sigma would take out the quasi macro and slap on a constant f2.8

TIA, Yuki

[Coco-Puffs]

oh c'mon.
someone has to have this lens.

[Mr. Clean]

I've got absolutely zero experience with the 18-50, but I loved the 17-70 I had! No complaints whatsoever with that lens!

[steved110]

I think having the longer range on the 17-70 makes it a more useful lens. It really is up to you to decide if you need or want a constant f/2.8 aperture, at the cost of reduced reach.

[Livinthalife]

I'm going through the same dillema, though I'm looking at the Tamron 28-70 2.8 or the 28-135 IS. They are running about the same prices on Yahoo auctions here.

[condyk]

... I'm looking at the Tamron 18-70 2.8 or the 28-135 IS. They are running about the same prices on Yahoo auctions here.

Personally, I don't think the 28-135 IS cuts it on a crop body. Not wide enough by a long shot and the IQ is very average. For coffee addicts only IMO ;-) Hard to look beyond the Sigma and Tamron at the moment, or if you wanna pay more the 17-40mm L. If you want length then the Sigma looks a great buy.

[JRD]

I'm torn between the 17-70 and 18-50 f2.8. I keep on hearing awesome reviews about the 17-70. Then here's this constant f2.8 lens thats in the range I want. BUT, I keep on seeing focus issues ALL OVER the internet.

Now, my question to my fellow POTN member is the 18-50 f2.8 (or wasnt-happy-with-it-and-returned-owners), are you, or are you not,happy with this lens?
If you aren't happy with it, can you tell me why please??

I just wish Sigma would take out the quasi macro and slap on a constant f2.8

TIA, Yuki

I have had the 18-50 for about a year and have taken ~5000 pictures with it so far on my 20D. It is my most-used lens. It's not perfect but it's pretty good. I like the size, weight and handling. Performance at F/2.8 is usable but not great (soft at edges, CA, vignetting) but it's better at F/4 and good at F/5.6 (comparable with my L lenses). Focussing is OK but I've used better. No HSM but that isn't really a factor - focus is fast and I don't mind the buzz.

When I bought it I think it was the best for the price, but there are more options available now and there may be better lenses for the price. I'd still recommend the 18-50 if you can pick it up for a good price though, if you can't afford the Canon 17-55, which is substantially better.

photozone.de has a realistic review of the strengths and weaknesses of the 18-50.

Best of luck!

John

[folkranger]

I have a 350d and bought a near new sigma 18-50, 2.8. On a range of tests it was never as sharp as the canon kit lens. so I got a refund.

I've bought a brand new sigma 18-50, 2.8. Just done some comparative tests tonight and get exactly the same results. blow up the pics to a sensible level and the canon kit lens is sharper than the sigma on all pics.I don't know if I can get my £250 back again and I'm at a loss what to do now. Any Suggestions, Pleeeeeeease.

[Coco-Puffs]

I have a 350d and bought a near new sigma 18-50, 2.8. On a range of tests it was never as sharp as the canon kit lens. so I got a refund.

I've bought a brand new sigma 18-50, 2.8. Just done some comparative tests tonight and get exactly the same results. blow up the pics to a sensible level and the canon kit lens is sharper than the sigma on all pics.I don't know if I can get my £250 back again and I'm at a loss what to do now. Any Suggestions, Pleeeeeeease.

this is exactly what I am afraid of...

[Coco-Puffs]

I have had the 18-50 for about a year and have taken ~5000 pictures with it so far on my 20D. It is my most-used lens. It's not perfect but it's pretty good. I like the size, weight and handling. Performance at F/2.8 is usable but not great (soft at edges, CA, vignetting) but it's better at F/4 and good at F/5.6 (comparable with my L lenses). Focussing is OK but I've used better. No HSM but that isn't really a factor - focus is fast and I don't mind the buzz.

When I bought it I think it was the best for the price, but there are more options available now and there may be better lenses for the price. I'd still recommend the 18-50 if you can pick it up for a good price though, if you can't afford the Canon 17-55, which is substantially better.

photozone.de has a realistic review of the strengths and weaknesses of the 18-50.

Best of luck!

John

there's no way I'm spending over a grand for a lens now. I was thinking about getting a used 10-20mm and a 18-50 f2.8 for around 700-800bucks :p. Those two lens would be enough for my needs.

I'm just scared of quality control here. and I really love the wide end, I find myself that the 18mm isnt wide enough. That 1mm on the wider end (compared to the 17-70) is the sole reason I'm considering the 17-70.

[Nick_C]

I find myself that the 18mm isnt wide enough. That 1mm on the wider end (compared to the 17-70) is the sole reason I'm considering the 17-70.

Surely 1mm makes hardly any difference?

[Nick_C]

I have a 350d and bought a near new sigma 18-50, 2.8. On a range of tests it was never as sharp as the canon kit lens. so I got a refund.

I've bought a brand new sigma 18-50, 2.8. Just done some comparative tests tonight and get exactly the same results. blow up the pics to a sensible level and the canon kit lens is sharper than the sigma on all pics.I don't know if I can get my £250 back again and I'm at a loss what to do now. Any Suggestions, Pleeeeeeease.

That is really hard to believe, although I do trust what your saying, but maybe there is a quality control problem going on with Sigma, because I found the kit lens to be really soft compared to my 17-70, I cant comment on the 18-50 but I think its on par with the 17-70 so it should have knocked spots off of the kit lens.

Nick :-)

[225719]

Since the 17-70 is this years new model and the fact that it is a newer production I have herd no complaints about soft copies... Purhaps its some thing they fixed.

[Nick_C]

Could be...

My one is softer at F2.8 but this is normal & is in line with all the reviews of the 17-70, at F5.6 or above its stunning, its the best lens ive had yet, the resolution figures are keeping up with Canon L lenses.

I went for the 17-70 instead of the 18-50 because of the cheaper price, better reach & if you look at the 18-50 review on photozone.de it really is quite bad at CA.

If the 17-70 is so good because its a new model, IE better manufacturing of lenses this year over previous years, then I cant wait to see what they bring out next.

Nick ;-)

[Digitalwave]

I had the same dilema as well. It was between the 18-50EX, the 17-70, or the 17-40L. I ruled the 17-40 out because I don't think the range is very usuable for my tastes. I ended up choosing the 18-50 because of the build and the constant f2.8. I didn't want a shifting aperture lens anymore.

The lens is a blast. Mine is sharp, and usuable at f/2.8 past 24mm. At 18mm f/2.8 its not as sharp as it could be. But for the price (1/4 the price of the 17-55IS) I think its a tremendous deal.

[Coco-Puffs]

Surely 1mm makes hardly any difference?

i know its only 1mm but it made a difference to me than the 20mm on the long end for some reason

[fatdeeman]

It's a great lens and higher in quality than the 17-70 (but not by a huge margin)

The trick is getting decent copy, mine is good optically but the autofocus can be very unreliable and this is a common complaint with this lens ive even seen reviews where they say the lens is soft and i can clearly see that they havent attained correct focus.

If you are in a position to try before you buy it would definatley be worth consideration.

Despite it's faults I like mine and have learned to get a decent focus 99% of the time, it's build quality is great, as is sharpness and colour and contrast, I just wish the focus was spot on and trustworthy all of the time like an EX SHOULD be.

The quality control seems to be a lot better with the 17-70 and I have been tempted to trade in just for the more reliable focusing more than the range which also would be appreciated.

But at the end of the day bad quality control is exactly what it is and doesn't define if the lens is a good design or not.

A good copy of the 18-50 will beat a 17-70 but the problem is that more often that not 18-50's are bad copies.

It's quite appaling how many people have issues with that lens including me.

If i knew i could get a decent copy i would just look for another 18-50 but that seems more unlikely each time i see another complaint.

I don't know if it's worth sending it to sigma or not, i dont even know if they have admitted there is an issues with the lens.

[folkranger]

Having tried two of these lenses now, my dealer was told by Sigma that the problem must lie with my camera. As I have a new ES 350d I am inclined to to trust canon's QC more than Sigma's opinion of Canon cameras.

I'm not sure whether the problem is lack of sharpness or poor focus but the blow ups show poor edge definition on the Sigma compared to the kit lens on EVERY shot. I'd be interested if knowing how you get 99% good focus if you've any tips.

[stewie-lives]

I had the 18-50 EX, which I sold to help buy the 17-55 EF-S for the IS feature. (I own the 30D)

From my experience, the 18-50 is an outstanding lens in its own right, but at 400 dollars, it's a no brainer buy for anyone on a budget. Sigma stands by their products and the lens comes with a 4 year warranty. I soundly and confidently ignore everyone's negative comments when it comes to a Sigma lens. My 105EX Macro kicks ass. I was never, not once, dissapointed with the 18-50.

My EF-S is only slightly better optically then my 'ole 18-50, and the only gripe I ever had about the Sigma was the audible buzz when focusing, and the speed of focusing.

From the all of the various comparisons between the 17-70 and the 18-50, only the 18-50 is compared, frequently, to the 17-40L and other nice lenses. Some comparisons aren't well done, and some are, all of the ones I've reviewed show the 18-50 to be superior optically then the 17-70. Look at who they're marketing to as well, the 17-70 is geared more to the weekend shooter, but the 18-50 is more select.

So long as there are no QC issues the 18-50 is excellent, if there are QC issues, you have a 4 year warranty... Ignore the monied sigma bashers, if we could all afford L glass, there would be a lot less debate. ;)

[folkranger]

After two lenses Sigma say it must be my camera at fault. Well they would say that.

I only bought the lens to get better sharpness than the kit lens as most forums said it was streets ahead. However both lenses have failed to achieve this 100% of the time.

My trials were using a tripod on a range of settings/subjects. Think I'll put the lens on ebay and go back to the kit lens which in my case is much better.

[folkranger]

I like mine and have learned to get a decent focus 99% of the time, it's build quality is great, as is sharpness and colour and contrast, I just wish the focus was spot on and trustworthy all of the time like an EX SHOULD be.



I'd love to know how you get decent focus 99% of time? :confused:

I'm much of a novice and use auto focus (can't see well enough to use manual these days anyway) but this gives poor sharpness or is it poor focus 100% compared to the kit lens.

I suppose it looks OK until seriously cropped which shows the kit lens pics much sharper.

[stewie-lives]

I'd love to know how you get decent focus 99% of time? :confused:

I'm much of a novice and use auto focus (can't see well enough to use manual these days anyway) but this gives poor sharpness or is it poor focus 100% compared to the kit lens.

I suppose it looks OK until seriously cropped which shows the kit lens pics much sharper.

if you took 100 samples of the kit lens and the Sigma, the Sigma would obviously stomp the kit lens. The sigma, lab tested at photozone, and complete with an excellent MTF chart is unquestionably superior to the kit lens - not only optically, but particulary in build quality. It's too bad you've been cheated out of an outstanding kit lens replacement. My camera is newer then yours and I had no problems to speak of - just a few thousand outstanding images perfectly focused and most of them taking full advantage of the 2.8 aperture.

[fatdeeman]

I'd love to know how you get decent focus 99% of time? :confused:

I'm much of a novice and use auto focus (can't see well enough to use manual these days anyway) but this gives poor sharpness or is it poor focus 100% compared to the kit lens.

I suppose it looks OK until seriously cropped which shows the kit lens pics much sharper.


The focus is usually out on the first half shutter press but if you half press the shutter twice the focus changes very slightly and 99% of the time the second press puts the focus right, you can even see it in the viewfinder if you look hard enough, with each alternating half press you can see it go between being focused and very slightly oof.

It's an annoying problem but I can overcome it because it's so predictable, almost everytime I take a picture I just half press the shutter twice and almost all my shots are sharp now where as before almost all of them were slightly out.

The thing that gets me is that the lens is obviosuly capable of getting it right so it must just be badly tuned or something, it's the difference between getting it right and getting it right the first time and it annoys me because the lens is obviously capable of working correctly.

Also because i'm aware of the problem I find myself checking the shots on the lcd way too much because even though i've learned to get consistantly sound focusing im always paranoid anyway because the lens shouldn't require two half presses almost every single time I take a photo.


If im shooting at f4 or above I only have to press the shutter once because the dof is sufficiant to supress the slight misfocus but at larger apertues it can make an enourmous difference. I use the lens wide open a lot and when it is correctly focused the sharpness even wide open is very impressive.

It's a shame that my only issue with the lens is quality control and not any kind of design fault or performance issue.

[Coco-Puffs]

ugh, i guess the only way to find out is for me to get a copy...or a 17-70 and forget about it....or wait for Tokina to release its price on the 16-50.

[folkranger]

if you half press the shutter twice the focus changes very slightly and 99% of the time the second press puts the focus .

Thanks, I'll try that. It's good to get a positive suggestion, Cheers.http://photography-on-the.net/forum/images/icons/icon7.gif

[folkranger]

I like the poll. Just sorry I'm in the unfortunate 12%.

[fatdeeman]

Thanks, I'll try that. It's good to get a positive suggestion, Cheers.http://photography-on-the.net/forum/images/icons/icon7.gif


Have a look here, scroll own a little to my posts :D

http://photography-on-the.net/forum/showthread.php?t=187402&page=2

[folkranger]

Have a look here, scroll own a little to my posts :D

http://photography-on-the.net/forum/showthread.php?t=187402&page=2

Just tried a few shots like you said.

There is more sharpness and a whole lot more contrast. Have you found that also?

Can't wait to try some more in proper daylight.

thankshttp://photography-on-the.net/forum/images/icons/icon14.gif

[Coco-Puffs]

how common is this problem?
or is that the chicken or the egg kinda question?

[fatdeeman]

Unfortunately from what I hear it's very common, but it seems to be limited to this lens and maybe the 18-125 sigma as well.

A lot of people say sigma has poor qc across the range but it's those two lenses I see the most complaints about.

My 10-20 was perfectly fine.

If you're in a position where you can exchange the lens if you get a bad copy I would say go for it especially as they have come down in price recently but if not then it's a no brainer really, get the 17-70 and you don't have to gamble on it being put together properly because I've heard nothing but praise for this lens.

[fatdeeman]

Just tried a few shots like you said.

There is more sharpness and a whole lot more contrast. Have you found that also?

Can't wait to try some more in proper daylight.

thankshttp://photography-on-the.net/forum/images/icons/icon14.gif


Let us know how you get on folk ranger

At least if it works we will have some sort of method to suggest to people who are having focus difficulties with the lens.

A workaround is better than nothing.

PS: Sigma if you are reading this (i wish) DO A RECALL you are selling faulty units and worse still they are from your top of the range EX brand! Canon were big enough to do it with the new IS zoom.

I wonder how many potential customers have been put off buying this lens through fear of recieving a bad copy. I have even seen (admitedly amatuer) reviews where the lens has been described as soft when I'm almost certain they have recived a copy that doesn't focus correctly.

I would send mine to sigma but I'm scared of getting it sent back and them saying my camera is to blame and I can't afford all that postage at the moment because I don't have a job.

I like sigma lenses, they are well built and feel nice to use and when they work correctly give excellent results and you also get a hood thrown in instead of being ripped off for a peice of molded plastic but the next time I buy a lens it probably won't be a sigma because I'm not willing to take another gamble.

All lenses, especially top of the range ones should come out of the factory working correctly.

I was interested by the new 50-150mm but the second I hear about focus issues i'm going to save up for a 70-200 L instead.

[nadtz]

I have one and like it, but Im kind of starting to eye that 17-55. When I got mine there was no other 2.8 that wasnt the 16-35 in that range, so overall Im very happy.*sigh* always more toys.

[tbrasington]

What about the Tamron 17-50 2.8? I have read quite a few good things on that lens.

[ed rader]

What about the Tamron 17-50 2.8? I have read quite a few good things on that lens.

that's the obvious choice for a constant f2.8 extended short zoom if you don't want to shell out for the canon 17-55 or wait to see if the tokina is any good.

the real world reviews of the tamron that i have seen so far have been very good.

ed rader

[Coco-Puffs]

i just dont understand why this problem is only on this forum. All the Japanese reviews I've seen doenst complain about the focus. Some magazines even compare it against the 17-40L over here and ranked it that the 17-40L > Sigma 18-50 2.8 = Tamron 18-50 2.8.

the most complain problem is the fact that the Sigma produces "cold" colors compared to others. i guess this is a problem to most Japanese b/c most of them dont even use photoshop.

[fatdeeman]

Well it depends on where they get thier samples from but anything submitted by sigma themselves to be tested will definatley be a example that works correctly.

That might have something to do with it.

[Coco-Puffs]

Well it depends on where they get thier samples from but anything submitted by sigma themselves to be tested will definatley be a example that works correctly.

That might have something to do with it.

no, its people who bought these personally and privately from a store. and most of them complain about how cold their images are.

[PEACHMAN]

I don't own either of these lenses, but do own some 2.8 lenses...I use the 2.8 very seldom and usually regret it when I do...I'd reather up the ISO and get grain than shoot as soft a picture as I usually get with 2.8....so my only advise is not to chose a 2.8 lens over another just for the 2.8...

[Nick_C]

Ive found the same too, indoors at F2.8 I get slightly softer focus, even if I could get a lens thats pin sharp at F2.8, I dont like the results indoors due to the lack of DOF.

I prefer to stop down a little, so lenses that have F2.8 all the way through do not sway my decision when purchasing..

Nick :-)

[fatdeeman]

no, its people who bought these personally and privately from a store. and most of them complain about how cold their images are.

Oh well that's fair enough then.

I did notice that fstopjojo compared this lens to the 17-85 efs and observed stronger saturation with the sigma.

[fatdeeman]

I don't own either of these lenses, but do own some 2.8 lenses...I use the 2.8 very seldom and usually regret it when I do...I'd reather up the ISO and get grain than shoot as soft a picture as I usually get with 2.8....so my only advise is not to chose a 2.8 lens over another just for the 2.8...


The thing is it's usually very sharp at f/2.8 every time but only if I half press the shutter twice to get the focus right.

I posted a link to my findings a page or two back in this thread.

If it wasn't for the focus issue the lens would be always sharp even wide open.

I have the focus issue at smaller apertures too but it decreases with each stop due to the DOF compensating but the point is the problems I've had with focus weren't a result of working with a shallow DOF

[fatdeeman]

Ive found the same too, indoors at F2.8 I get slightly softer focus, even if I could get a lens thats pin sharp at F2.8, I dont like the results indoors due to the lack of DOF.

I prefer to stop down a little, so lenses that have F2.8 all the way through do not sway my decision when purchasing..

Nick :-)


See my grievance with this lens is that it's VERY sharp wide open and stopped down and that the focus issue happens wide open AND stopped down but obviously the more I stop down the less of a problem it is due to the increased DOF.

I agree with your point and in most cases I don't shoot wide open either but what annoys me is that the soft focus I get isn't related to shallow DOF but to a fault with the lens.

Knowing the lens can be sharp but also knowing that I'll have to half press a couple of times and then check the image on the lcd to make sure it's sharp is annoying and it doesn't just happen wide open, it happens at f/4 f/5.6 and so on but with each stop it becomes less apparent and by f/8 the DOF is sufficiant to suppress the problem.

[Nick_C]

That is a VERY annoying problem, especially if you want to capture something quickly, the first shot would be ruined.

Might be worth trading it in for the 17-70 or something else, I can honestly say I havent been anything but happy with my lens, I would like it to be sharper at 2.8, but if I had a £2000 lens im sure I would still be moaning about the 2.8 end being softer, its a great lens for the money.

Nick ;-)

[fatdeeman]

I've definatley been giving though to getting the 17-70.

It's nice to just be able to shoot away and know that the majority of shoots will turn out in focus.

[Coco-Puffs]

im still debating.

Theres one for in Tokyo today for 270bucks. but not for an EOS mount. Id jump on it if its around 250 for an EOS. The camera store I always buy gives guarentee for a few weeks. and Ive only seen one used 17-70 for an EOS show up. The EOS mount used 18-50 EXs are about 320 still.

[Nick_C]

I was travelling along in the car & was just shooting away through the windscreen, its not as good as actually getting out the car but I did manage to get some unique shots of motorway stuff that I couldnt normally get, I had my 350D on burst mode along with the AIServo & with the focussing speed of the 17-70 I had roughly 1 out of 10 shots blurred.

I had a few photos though that were REALLY blurry where focus was way off, on a closer inspection I noticed the camera had been focussing through the glass on far away stuff, then suddenly focused on the actual glass, as it has tiny little heating wires in the glass & it got these in perfect focus, so its not great shooting like this, but it shows the focus speed was pretty good to be able to change from distant tracking to really close & then back again with only 1 or 2 shots ruined.

It helps to actually get out of the car!! lol..

Nick :-)

[gcogger]

I used my 18-50 at a (motorsport) rally not too long ago. In AI servo mode it was easily able to track the cars into and out of corners - the success rate was about the same as with my Canon 70-200 f/4 L. It was even working well when the light was getting bad.

[Coco-Puffs]

hmm.... i guess it depends on the copy then.

[Coco-Puffs]

i got play with a 18-50EX at the store today.
i played with two copies but one had horrible AF issues.
the other one focused ok (at least to the naked eye via view finder and magnification on a the screen).

[fatdeeman]

Well if you're in a position to try before you buy it would probably be worthwhile getting one because like I say, when I can get mine to focus right it's an amazing little lens.

I wish I could rely on the autofocus but I can work around it, there's not many lenses I would bother hanging on to knowing they had such issues.

I find the sharpness even wide open to be impressive and the colours always seem vibrant too.